Not Applicable
Not Applicable
1. Field of the Invention
The present invention relates to internal combustion engines of the type that has a vertical crankshaft, and to mechanisms for coupling accessory devices to be driven by an engine.
2. Description of the Related Art
Many types of power equipment, such as walk-behind and riding lawnmowers, utilize an internal combustion engine which has a vertically oriented crankshaft. Such engines have one or more horizontally aligned piston chambers so that the pistons drive the crankshaft to rotate about a vertical axis. The crankshaft extends from the bottom of the engine where the implement being driven is attached. For example, a pulley or sprocket often is connected to this lower portion of the crankshaft to drive the blades and wheels of a lawnmower. The upper end of the vertical crankshaft typically connects to a flywheel and starter mechanism and does not extend out of the engine housing.
In some power equipment, it is desirable that the engine also power accessory devices, in addition to the primary implements such as the blade and wheels for a lawnmower. Heretofore, the common technique employed by these and other types of power equipment was to drive such accessories from a coupling attached to the bottom end of the engine""s crankshaft. For example, U.S. Pat. No. 6,155,035 describes a power take-off which couples the engine of a walk-behind lawnmower to a chipper-shredder placed alongside. U.S. Pat. No. 4,965,990 discloses attachment of an edger assembly to a walk-behind lawnmower. Thus all of the equipment driven by the engine receives power from that same end of the crankshaft.
After an engine has been assembled unto a piece of power equipment, such as a lawnmower, it may be extremely difficult for a user to attach accessories that require power from the engine. The power equipment manufacturer often mounts the engine on the frame of the equipment in such a manner where further access to the lower end of the crankshaft is difficult or impossible. Unless the power equipment manufacturer provides a power take-off coupling, additional accessories often cannot be connected to the engine. Even when a power take-ff coupling is provided, it often requires exposed belts, chains or shafts which present a safety hazard.
Therefore, it is desirable to provide a power take-off coupling on the engine which is easily accessible after the engine has been mounted on a piece of power equipment and wherein the coupling have exposed moving parts.
An internal combustion engine includes a crankcase and a crankshaft mounted vertically in the crankcase. The crankshaft has a first end that extends outwardly from the bottom of the crankcase for attachment to an implement to be driven by the engine. Another end of the crankshaft extends outwardly from the top of the crankcase and has a coupling to engage an accessory device.
In the preferred embodiment, a cover extends over the top of the crankcase.
The cover has an exterior surface from which a well extends toward the crankcase. The coupling projects into the well, but does not extend outwardly beyond the exterior surface of the cover. The well enables the accessory device to engage the coupling and that be driven by the engine. However the well shields the rotating coupling from inadvertent contact by the user of the equipment on which the engine is mounted. A cap also may close the well when an accessory device is not connected to the coupling to further safeguard against inadvertent contact.